This invention relates generally to an improved system and method for detecting and monitoring fluid flow parameters such as liquid flow within a conduit. More particularly, this invention relates to a sensing system and method for measuring fluid flow velocity, temperature and pressure in a nonintrusive or noninvasive manner.
Fluid flow conduits are widely used in industrial processes and the like to deliver fluids in liquid or gaseous form from one location to another. In many instances, it is necessary or desirable to monitor the fluid flow to insure proper and/or safe operation of process equipment. As one example, in a nuclear power plant facility, it is necessary to monitor various liquid flow parameters such as flow rate, temperature, and pressure. Accordingly, in the prior art, a variety of flow monitoring devices and techniques have been developed for this purpose. However, in general, these prior art devices and methods for monitoring fluid flows have utilized invasive temperature and/or pressure probes mounted to extend through ports in a flow conduit into direct contact with the fluid flow stream. This requirement for probe ports in the conduit typically results in a monitoring system which is relatively costly to fabricate and maintain, and further wherein the probe ports present leakage sites for escape of potentially hazardous process fluid.
In recent years, noninvasive sensing systems have been developed particularly for use in monitoring certain flow parameters of a liquid flow within a conduit. Such noninvasive systems have utilized ultrasonic transducers mounted on the exterior of a flow conduit and adapted to bidirectionally transmit and receive pulsed signals diagonally through the conduit and flow stream therein. By measuring the upstream and downstream transit times of these pulsed signals, it is possible to calculate the flow velocity of the liquid flow steam. Moreover, with this transit time information, it is also possible to calculate the speed of sound in the liquid flow stream.
While noninvasive sensing systems of the type described above are extremely desirable in many operating environments, their practical utility has been limited to monitoring of a relatively small number of flow parameters. More specifically, noninvasive systems have not been designed for obtaining accurate and reliable measurements of the temperature and pressure of the flow stream. To obtain measurements of temperature and pressure, resort to invasive type monitoring devices has generally been required.
There exists, therefore, a significant need for further improvements in sensing systems and methods for noninvasive monitoring of fluid flow within a conduit, particularly with respect to monitoring of additional fluid parameters such as temperature and pressure. The present invention fulfills these needs and provides further related advantages.